diff --git a/include/bgfx.c99.h b/include/bgfx.c99.h
index fa01f3ed8..c4f5270b2 100644
--- a/include/bgfx.c99.h
+++ b/include/bgfx.c99.h
@@ -152,13 +152,15 @@ typedef enum bgfx_uniform_type
 
 typedef enum bgfx_backbuffer_ratio
 {
-    BGFX_BACKBUFFER_RATIO_NONE,
     BGFX_BACKBUFFER_RATIO_EQUAL,
     BGFX_BACKBUFFER_RATIO_HALF,
     BGFX_BACKBUFFER_RATIO_QUARTER,
     BGFX_BACKBUFFER_RATIO_EIGHTH,
     BGFX_BACKBUFFER_RATIO_SIXTEENTH,
-    BGFX_BACKBUFFER_RATIO_DOUBLE
+    BGFX_BACKBUFFER_RATIO_DOUBLE,
+
+    BGFX_BACKBUFFER_RATIO_COUNT
+
 } bgfx_backbuffer_ratio_t;
 
 #define BGFX_HANDLE_T(_name) \
diff --git a/include/bgfx.h b/include/bgfx.h
index 5a623dd81..f8a80bcd8 100644
--- a/include/bgfx.h
+++ b/include/bgfx.h
@@ -193,13 +193,14 @@ namespace bgfx
 	{
 		enum Enum
 		{
-			None,
 			Equal,
 			Half,
 			Quarter,
 			Eighth,
 			Sixteenth,
 			Double,
+
+			Count
 		};
 	};
 
diff --git a/src/bgfx.cpp b/src/bgfx.cpp
index f82eff81d..6bbae9e4f 100644
--- a/src/bgfx.cpp
+++ b/src/bgfx.cpp
@@ -2407,7 +2407,7 @@ again:
 	{
 		BGFX_CHECK_MAIN_THREAD();
 		BX_CHECK(NULL != _mem, "_mem can't be NULL");
-		return s_ctx->createTexture(_mem, _flags, _skip, _info, BackbufferRatio::None);
+		return s_ctx->createTexture(_mem, _flags, _skip, _info, BackbufferRatio::Count);
 	}
 
 	void getTextureSizeFromRatio(BackbufferRatio::Enum _ratio, uint16_t& _width, uint16_t& _height)
@@ -2453,7 +2453,7 @@ again:
 		uint32_t magic = BGFX_CHUNK_MAGIC_TEX;
 		bx::write(&writer, magic);
 
-		if (BackbufferRatio::None != _ratio)
+		if (BackbufferRatio::Count != _ratio)
 		{
 			_width  = uint16_t(s_ctx->m_frame->m_resolution.m_width);
 			_height = uint16_t(s_ctx->m_frame->m_resolution.m_height);
@@ -2477,11 +2477,12 @@ again:
 
 	TextureHandle createTexture2D(uint16_t _width, uint16_t _height, uint8_t _numMips, TextureFormat::Enum _format, uint32_t _flags, const Memory* _mem)
 	{
-		return createTexture2D(BackbufferRatio::None, _width, _height, _numMips, _format, _flags, _mem);
+		return createTexture2D(BackbufferRatio::Count, _width, _height, _numMips, _format, _flags, _mem);
 	}
 
 	TextureHandle createTexture2D(BackbufferRatio::Enum _ratio, uint8_t _numMips, TextureFormat::Enum _format, uint32_t _flags)
 	{
+		BX_CHECK(_ratio < BackbufferRatio::Count, "Invalid back buffer ratio.");
 		return createTexture2D(_ratio, 0, 0, _numMips, _format, _flags, NULL);
 	}
 
@@ -2523,7 +2524,7 @@ again:
 		tc.m_mem = _mem;
 		bx::write(&writer, tc);
 
-		return s_ctx->createTexture(mem, _flags, 0, NULL, BackbufferRatio::None);
+		return s_ctx->createTexture(mem, _flags, 0, NULL, BackbufferRatio::Count);
 	}
 
 	TextureHandle createTextureCube(uint16_t _size, uint8_t _numMips, TextureFormat::Enum _format, uint32_t _flags, const Memory* _mem)
@@ -2563,7 +2564,7 @@ again:
 		tc.m_mem     = _mem;
 		bx::write(&writer, tc);
 
-		return s_ctx->createTexture(mem, _flags, 0, NULL, BackbufferRatio::None);
+		return s_ctx->createTexture(mem, _flags, 0, NULL, BackbufferRatio::Count);
 	}
 
 	void destroyTexture(TextureHandle _handle)
@@ -2628,6 +2629,7 @@ again:
 
 	FrameBufferHandle createFrameBuffer(BackbufferRatio::Enum _ratio, TextureFormat::Enum _format, uint32_t _textureFlags)
 	{
+		BX_CHECK(_ratio < BackbufferRatio::Count, "Invalid back buffer ratio.");
 		_textureFlags |= _textureFlags&BGFX_TEXTURE_RT_MSAA_MASK ? 0 : BGFX_TEXTURE_RT;
 		TextureHandle th = createTexture2D(_ratio, 1, _format, _textureFlags);
 		return createFrameBuffer(1, &th, true);
diff --git a/src/bgfx_p.h b/src/bgfx_p.h
index 8b9f12eaf..1a6b199a8 100644
--- a/src/bgfx_p.h
+++ b/src/bgfx_p.h
@@ -1921,7 +1921,7 @@ namespace bgfx
 			{
 				uint16_t textureIdx = m_textureHandle.getHandleAt(ii);
 				const TextureRef& textureRef = m_textureRef[textureIdx];
-				if (BackbufferRatio::None != textureRef.m_bbRatio)
+				if (BackbufferRatio::Count != textureRef.m_bbRatio)
 				{
 					TextureHandle handle = { textureIdx };
 					resizeTexture(handle
@@ -2795,7 +2795,7 @@ namespace bgfx
 		void resizeTexture(TextureHandle _handle, uint16_t _width, uint16_t _height)
 		{
 			const TextureRef& textureRef = m_textureRef[_handle.idx];
-			BX_CHECK(BackbufferRatio::None != textureRef.m_bbRatio, "");
+			BX_CHECK(BackbufferRatio::Count != textureRef.m_bbRatio, "");
 
 			getTextureSizeFromRatio(BackbufferRatio::Enum(textureRef.m_bbRatio), _width, _height);